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21 results on '"Kostura, Bruno"'

15. Retention of phosphates from aqueous solutions with in sol–gel-derived amorphous CaO–MgO–Al2O3–SiO2 system as a model of blast furnace slag.

Author

Kostura, Bruno, Huczala, Radim, Ritz, Michal, and Leško, Juraj

Abstract

The article proposes new possibilities for the estimation of the maximum phosphate retention capacities (PRC) in blast furnace slags using their modeling. The amorphous blast furnace slag model (BFS–SG) and slag samples along the joining of the CaO:SiO2 = 1 and (CaO + MgO):SiO2 = 1 of the CaO–MgO–Al2O3–SiO2 phase diagram were prepared by the sol–gel method. The surface analysis of BFS–SG was performed and the results were compared with real BFS. Batch adsorption experiments were performed to evaluate the phosphate removal of slags. SEM analysis and Raman spectroscopy were used to identify phosphate adsorbed forms. Phosphate retention is realized by the surface reactions of hydration products resulting in a nanostructured Ca-hydroxyapatite. The acid–base properties of the model samples in the selected cross-sections were characterized by the values of the optical basicity. An excellent linear relation between the phosphorus retention capacity (PRC) and the optical basicity of the model samples was found, which allows an estimation of slag retention capacities and the forms of adsorbed phosphorus. [ABSTRACT FROM AUTHOR]

Published
2018
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16. Selektivní odstraňování Cu(II) z odpadních vod obsahujících fosfáty pomocí oxyhumolitu.

Author

Kostura, Bruno, Kohutová, Hana, Kostura, Bruno, and Kohutová, Hana

Abstract

Diplomová práce je zaměřena na odstranění těžkých kovů (Cu) z odpadních vod obsahujících fosfáty pomocí oxyhumolitu. Zkoumaly se faktory ovlivňující adsorbované množství (adsorpční kapacitu) a adsorpční účinnost. Jednalo se o pH roztoku, koncentraci kovu (Cu), přítomnost fosfátů a dobu sorpce. Pro stanovení obsahu kovu v roztoku byla použita atomová adsorpční spektrometrie a pro stanovení obsahu fosfátů spektrofotometická metoda. Vliv pH na adsorpci mědi byl výrazný. Průběh adsorpce mědi i fosfátů odpovídá Freundlichově izotermě. Maximální sorpční kapacita pro měď při pH = 3,9 byla 1,6059 mmol g-1. Pro selektivní odstranění mědi z vodných roztoků s obsahem fosfátů je vhodné upravit pH na rozmezí hodnot 3,6 - 3,9. Při těchto hodnotách pH se odstraní až 95 % mědi a průměrně jen 13,13 % fosforu. Adsorpce je poměrně rychlá a rovnováha se ustálila již po 20 minutách., The thesis is oriented on removal of heavy metals (Cu) from phosphates containing wastewaters by oxihumolite. Examined the factors influencing the adsorbed amount (adsorption capacity) and adsorption efficiency. This was the solution pH, concentration o metal (Cu), for the presence of phosphates and sorption time. The atomic adsorption spectrometry was used for determination of the amount of metal in the solution and for the determination of phosphates was used spectrofotometry method. Effect of pH on the adsorption of copper was significant. The course of adsortion of Cu and phosphates corresponds to the Freundlich isotherm. The maximum sorption capacity for Cu at pH = 3.9 was 1.6059 mmol g-1. Fro selective removal of Cu from solutions containing phosphates should be adjusted to pH values ranging from 3.6 to 3.9. At these pH values are removed up to 95 % copper and an average of only 13.13 % phosphorus. Adsorption is relatively fast and equilibrium is stabilized after 20 min., Ve zpracování, Import 29/09/2010

Published
2010

19. Retention of phosphates from aqueous solutions with in sol–gel-derived amorphous CaO–MgO–Al2O3–SiO2system as a model of blast furnace slag

Author

Kostura, Bruno, Huczala, Radim, Ritz, Michal, and Leško, Juraj

Abstract

The article proposes new possibilities for the estimation of the maximum phosphate retention capacities (PRC) in blast furnace slags using their modeling. The amorphous blast furnace slag model (BFS–SG) and slag samples along the joining of the CaO:SiO2= 1 and (CaO + MgO):SiO2= 1 of the CaO–MgO–Al2O3–SiO2phase diagram were prepared by the sol–gel method. The surface analysis of BFS–SG was performed and the results were compared with real BFS. Batch adsorption experiments were performed to evaluate the phosphate removal of slags. SEM analysis and Raman spectroscopy were used to identify phosphate adsorbed forms. Phosphate retention is realized by the surface reactions of hydration products resulting in a nanostructured Ca-hydroxyapatite. The acid–base properties of the model samples in the selected cross-sections were characterized by the values of the optical basicity. An excellent linear relation between the phosphorus retention capacity (PRC) and the optical basicity of the model samples was found, which allows an estimation of slag retention capacities and the forms of adsorbed phosphorus.

Published
2018
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21. Oxyhumolite as a Sorbent of CuII from Phosphate-Containing Solutions.

Author

Kohutová, Hana, Kostura, Bruno, and Kukutschová, Jana

Subjects
*PHOSPHATES, *COPPER compounds, *SOLUTION (Chemistry), *ADSORPTION (Chemistry), *HYDROGEN-ion concentration, *HUMIC acid
Abstract

This study explores the use of oxyhumolite (OX) for sorption removal of CuII from sewage containing phosphates. It was discovered that the adsorption of CuII markedly depends on pH and linearly increases with increasing pH values. Adsorption efficiency of OX for phosphates is approximately constant ( E≈13%) and does not depend on the pH value. The optimum pH range for the selective sorption was determined to be between 3.3-3.7 ( ECu≈90%). The good sorption efficiency for CuII results from the high content of humic acids and the presence of inorganic components. [ABSTRACT FROM AUTHOR]

Published
2012
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